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U.S. Department of Homeland Security Seal. ICS-CERT. Industrial Control Systems Cyber Emergency Response Team.

Advisory (ICSA-18-025-01)

Nari PCS-9611

Original release date: January 25, 2018 | Last revised: February 01, 2018

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CVSS v3 9.8

ATTENTION: Remotely exploitable/low skill level to exploit.

Vendor: Nari

Equipment: PCS-9611

Vulnerability: Improper Input Validation


All versions of the PCS-9611 relay, a control and monitoring unit, are affected.


Successful exploitation of this vulnerability could allow a remote attacker arbitrary read/write abilities on the system.


NCCIC has reached out to Nari but has not received a response.

NCCIC recommends users take defensive measures to minimize the risk of exploitation of this vulnerability. Specifically, users should:

  • Minimize network exposure for all control system devices and/or systems, and ensure that they are not accessible from the Internet.
  • Locate control system networks and remote devices behind firewalls, and isolate them from the business network.
  • When remote access is required, use secure methods, such as Virtual Private Networks (VPNs), recognizing that VPNs may have vulnerabilities and should be updated to the most current version available. Also recognize that VPN is only as secure as the connected devices.

NCCIC reminds organizations to perform proper impact analysis and risk assessment prior to deploying defensive measures.

NCCIC also provides a section for control systems security recommended practices on the ICS-CERT web page. Several recommended practices are available for reading and download, including Improving Industrial Control Systems Cybersecurity with Defense-in-Depth Strategies.

Additional mitigation guidance and recommended practices are publicly available in the NCCIC Technical Information Paper, ICS-TIP-12-146-01B--Targeted Cyber Intrusion Detection and Mitigation Strategies, that is available for download from the ICS-CERT web site.

Organizations observing any suspected malicious activity should follow their established internal procedures and report their findings to NCCIC for tracking and correlation against other incidents.

No known public exploits specifically target this vulnerability.


An improper input validation vulnerability has been identified that affects a service within the software that may allow a remote attacker to arbitrarily read/access system resources and affect the availability of the system.

CVE-2018-5447 has been assigned to this vulnerability. A CVSS v3 base score of 9.8 has been assigned; the CVSS vector string is (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H).


Kirill Nesterov and Alexey Osipov from Kaspersky Labs reported the vulnerability to NCCIC.


Critical Infrastructure Sectors: Energy

Countries/Areas Deployed: Asia

Company Headquarters Location: China

Contact Information

For any questions related to this report, please contact the NCCIC at:

Toll Free: 1-888-282-0870

For industrial control systems cybersecurity information:  http://ics-cert.us-cert.gov 
or incident reporting:  https://ics-cert.us-cert.gov/Report-Incident?

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